Thyroid Research Thyroid Research Archive Hyperthyroidism

Hyperthyroidism from the dietary supplement tiratricol (3,5,3' -triiodothyroacetic acid)

(November 2002)

The background of the study. Tiratricol (3,5,3' -triiodothyroacetic acid, or triac) is marketed as a substance that accelerates metabolism and burns fat. It is a thyroid hormone analog with some thyroid activity; as reported in this paper it can cause symptoms of hyperthyroidism.

Case report. An 87-year-old woman was referred to the Mayo Clinic for nervousness, insomnia, fatigue, tremor, and weight loss. Four months earlier she had been advised to take multiple dietary supplements, including tiratricol. The dose of tiratricol was three 1000- µg tablets daily. Her symptoms began two months later. Physical examination was normal. Her serum thyrotropin (TSH) concentration was low (0.015 mU/L), her serum free thyroxine (T4) concentration was low (0.6 ng/dl [7.7 pmol/L]), and her serum triiodothyronine (T3) concentration was high (293 ng/dl [4.5 nmol/L]), probably because tiratricol was measured as T3. Six months earlier her serum TSH concentration had been normal (2.9 mU/L).

The patient was advised to stop all supplements. She improved, and four weeks later her serum TSH concentration was 5.9 mU/L and her serum T4 and T3 concentrations were normal. She then resumed the supplements, except for tiratricol. Her symptoms did not recur, and six weeks later tests of thyroid function were normal.

The conclusions of the study. Tiratricol, a thyroid hormone analog marketed as a dietary supplement, can cause symptoms of hyperthyroidism.

The original article. Bauer BA, Elkin PL, Erickson D, Klee GG, Brennan MD. Symptomatic hyperthyroidism in a patient taking the dietary supplement tiratricol. Mayo Clin Proc 2002;77:587-90.